In my last blog, I wrote about recent confusion regarding the recent and future generations of Wi-Fi technology.
Quite frankly, much of the confusion is a result of all the recent marketing buzz about the future generation of Wi-Fi 7. Wi-Fi 7 will be based on much of the technology currently being defined by the IEEE in a draft amendment, 802.11be, also known as the Extremely High Throughput (EHT) Wi-Fi technology. However, it is important to understand that the IEEE and the Wi-Fi Alliance are two separate organizations. The IEEE 802.11 task group defines the WLAN standards, and the Wi-Fi Alliance defines interoperability certification programs. Furthermore, everyone should understand that Wi-Fi 7 does not yet exist because there is no certification testing yet of the technology. Let me explain.
The Wi-Fi Alliance is a global, nonprofit industry association of more than 550 member companies devoted to promoting the growth of Wi-Fi technology. One of the primary tasks of the Wi-Fi Alliance is to market the Wi-Fi brand and raise consumer awareness of new 802.11 technologies as they become available. And they have done an amazing job because I contend that the brand of Wi-Fi is as well recognized as Band-Aid or Coca-Cola. Because of the Wi-Fi Alliance’s overwhelming marketing success, most worldwide Wi-Fi users are likely to recognize the Wi-Fi logo, as shown in Figure 1.
Figure 1 – Ensure that your Wi-Fi devices are compatible
The Wi-Fi Alliance’s main task is ensuring Wi-Fi products’ interoperability by providing certification testing. The goal is to ensure compatibility between Wi-Fi devices. Products that pass the Wi-Fi certification process receive a Wi-Fi Interoperability Certificate that includes detailed information about the individual product’s Wi-Fi certifications.
There are many essential interoperability certifications, including WPA3 for security and the most recent certification for Wi-Fi 6 technology. Please note that Wi-Fi Certified 6 validates many 802.11ax mechanisms, including operations in the newly available 6 GHz frequency band. Wi-Fi 6E is effectively a marketing name used to reference Wi-Fi 6 technology in 6 GHz.
On May 16, 2022, the Wi-Fi Alliance announced this about a future Wi-Fi 7 certification for interoperability:
So, there is no Wi-Fi 7 certification yet. Now, this does not mean that the technology is not being developed. And very often, Wi-Fi products hit the marketplace before the certification program is in place, especially consumer-grade Wi-Fi products. As a matter of fact, on April 12, 2022, Broadcom announced their Wi-Fi 7 ecosystem. They announced Wi-Fi 7 chipsets and radios for residential APs and client devices such as smartphones. They also announced Wi-Fi 7 enterprise access point chips. Broadcom is a valued technology partner of Extreme Networks, and we use their enterprise-grade radios in all Extreme APs.
Recently, on September 8th, Intel’s Carlos Cordeiro and Broadcom’s Vijay Nagarajan collaborated for a really cool video of a cross-vendor Wi-Fi 7 demonstration with over-the-air speeds greater than 5 gigabits per second.
Only 5 Gbps? You might have heard Wi-Fi 7 marketing claims of up to 30 Gbps! First, let’s be honest, there will not be real-world speeds of 30 Gbps. When you digest that marketing claim, please take it with many grains of salt. Defined data rates are always theoretical, and due to medium contention, the actual TCP throughput is usually about 50-60% of any advertised Wi-Fi data rate being used. I will say that the Intel and Broadcom video demo was impressive, with speeds of 5 Gbps under controlled conditions. And I so think real-world multi-gig Wi-Fi speeds will indeed become more common, especially in the consumer market where multi-gig broadband initiatives are being announced.
Now keep in mind that despite all the hoopla, we can’t sell you Wi-Fi 7 technology yet for the enterprise. That is at least 18 months out and probably longer. Which brings me to the question I asked in the title of this blog, “Is the next generation, Wi-Fi 7, meant for the consumer or enterprise markets?”
There are a lot of new promised bells and whistles in Wi-Fi 7. However, the two features that seem to get a lot of current marketing hype are 4K QAM modulation and 320 MHz wide channels in 6 GHz. Both features contribute to some of the shocking claims of theoretical speeds of up to 30 Gbps. However, I believe that the 4K QAM and 320 MHz wide channels are pretty much consumer-grade features.
Quadrature amplitude modulation (QAM) combines both phase and amplitude modulation. A constellation diagram, also known as a constellation map, is a two-dimensional diagram often used to represent QAM modulation. A constellation diagram is divided into four quadrants, and different locations in each quadrant can be used to represent data bits. The more complex the modulation, the more constellation finite data points there are the diagram.
As shown in Figure 2, with every generation of Wi-Fi, a new complex modulation is introduced that promises greater data rates and increased throughput. The enhanced technology and receive sensitivity of each generation of Wi-Fi radio make this possible. However, the more complex the QAM modulation, the more pristine the RF environment must be so radios can interpret the modulated data. For example, 256-QAM requires a signal-to-noise ratio (SNR) of 29 dB or higher. 1024-QAM modulation requires a very-high SNR threshold of 35 DB. The 4096-QAM, also known as 4K-QAM, will probably need an SNR environment of 40 DB or more. That means a pristine RF environment with an extremely low noise floor. In the real world, this will probably be achievable with 6 GHz channels deployed on 1-2 APs in a household environment. And might be possible when the Wi-Fi 7 client is within 5 meters of the Wi-Fi 7 AP. But this simply is not practical in the enterprise where there will be numerous APs, mobile clients with greater distance, and variable noise floors depending on the deployment vertical and location.
Figure 2 – QAM modulation
The promise of ultra-wide 320 MHZ channels also gets a lot of hype when discussing Wi-Fi 7. The wider the channel, the more data can be modulated on the additional frequency space. This gives you incredibly high potential data rates. Think about it, sixteen times more data can be transmitted on a 320 MHz channel in 6 GHz than a 20 MHz channel commonly used in 2.4 and 5 GHz. Sounds great, right?
Figure 3 – Big channels in 6 GHz
Because multiple APs are deployed in the enterprise, channel reuse patterns will be needed in 6 GHz, just like the legacy bands. There is more frequency space in 6 GHz, and the new power spectral density rules actually make it advantageous to use larger channels. 80 MHz channel reuse patterns in the enterprise will be common in countries with the entire 1,200 MHz of 6 GHz frequency space available. In Europe, 40 MHz will probably be more common because twelve 40 MHz channels are available for a reuse plan, but only six 80 MHz channels.
So why not 320 MHz channels? Well, depending on the region and available 6 GHz spectrum, you will only have one or three 320 channels available. While this might work well for one AP in an isolated area, this will not work in an enterprise channel reuse pattern because of co-channel interference (CCI) and the resulting medium contention overhead. By the way, 160 MHz channels will not be used in the enterprise except in corner cases for the same reasons.
The 320 MHz channel is a Wi-Fi 7 consumer-grade feature for when 1-2 APs deployed in a household. As a matter of fact, I fully expect 320-MHz channels to be the default setting when consumer-grade home Wi-Fi routers hit the market. The only problem with that is that the consumer-grade routers with that default setting will likely cause primary/secondary OBSS interference when located near enterprise deployments. Bigger is not always better.
So, are there any Wi-Fi 7 features that will have value in the enterprise? Yes, I believe multi-link operation (MLO) holds great potential. When discussing MLO, think of multiple bands and multiple channel connectivity between a Wi-Fi 7 AP and a Wi-Fi 7 client, as shown in Figure 4. This capability has many potential methods where multiple Wi-Fi links could be used for link steering, link redundancy, and link aggregation. The respective goals are lower latency, increased reliability, and higher throughput. Multi-link operations can be potentially synchronous or asynchronous.
Figure 4 – Multi-link operation (MLO)
My personal belief is that multi-link operation (MLO) will have a future impact in supporting mission-critical and industrial enterprise applications that require reduced latency and jitter. Although often hyped, I believe we will see a renaissance of innovation in augmented reality (AR) and virtual reality (VR) applications where MLO will hold value. As I stated, there are multiple proposed methods for MLO, and I will discuss them in future blogs.
So, what can we conclude? As I discussed in this video, I think we sometimes get too caught up with the new “bells and whistles” of various generations of Wi-Fi. It’s not always about features and updates, and the most significant thing happening in Wi-Fi right now is that it’s all about the 6 GHz spectrum. Wi-Fi 7 will bring us both consumer-grade and enterprise features, but the real value is when these futuristic features begin to prosper in 6 GHz.
In the meantime, think of Wi-Fi 6E as the foundational generation of Wi-Fi that offers 6 GHz connectivity. Wi-Fi 7 will be the next generation that leverages 6 GHz. As a matter of fact, Wi-Fi 7, Wi-Fi 8, and other future generations of Wi-Fi will be built upon the 6 GHz spectrum foundation that has debuted with Wi-Fi 6E.
